1. Field of the Invention
The present invention relates to trailer hitches. In particular, the invention relates to trailer hitches having locking devices for preventing the trailer from accidently disconnecting from a ball hitch on the towing vehicle.
2. Description of the Related Art
It is known in the art that trailers sometimes become accidently disconnected from the vehicle which is towing the trailer. Such accidental disconnections can cause damage to the trailer and the equipment carried thereon. Other vehicles traveling on the highway on which the trailer is being towed can be damaged by the accidently disconnected trailer, and the occupants of the other vehicles struck by the accidently disconnected trailer may suffer serious or fatal injuries.
Ball trailer hitches are usually bolted to the bumper or towing bar of the towing vehicle, and the nut holding the ball hitch to the trailer may come unthreaded from the bolt holding the ball hitch to the towing vehicle. Furthermore, the bolt holding the ball hitch to the trailer may shear off the towing vehicle.
Trailers are commonly required to have additional hitching devices such as safety chains thereon to prevent the trailer from becoming detached from the towing vehicle if the primary trailer hitch, such as a common ball hitch or the like, becomes disconnected. However, safety chains frequently break after the trailer becomes accidently separated from the primary trailer hitch. The safety chains many trailers have allow the trailer tongue to drag on the road after accidental disconnection of the ball hitch. When the trailer tongue drags on the road, the trailer tongue may hit a hole or irregularity in the road and break the safety chains or flip the trailer.
Exemplary of the Patents of the related art are the following U.S. Pat. Nos. 5,378,008; 5,161,815; 4,774,823; 4,428,596; 4,211,428; 3,549,173; 3,393,924; and 3,326,576.